People August 19th 2015
Shannen Doherty is battling breast cancer, she reveals to PEOPLE exclusively.

"Yes, I have breast cancer, and I am currently undergoing treatment," the actress said in an exclusive statement to PEOPLE.

"I am continuing to eat right, exercise and stay very positive about my life," she continued. "I am thankful to my family, friends and doctors for their support and, of course, my fans who have stood by me."

Doherty, 44, was forced to disclose the illness after legal documents surfaced on TMZ, revealing that the actress was suing her former business manager for failing to pay her insurance premiums, allowing her health insurance to lapse, during which time she did not receive medical care.

According to the lawsuit, the actress, who is married to photographer Kurt Iswarienko, was first diagnosed in March 2015. She "discovered that she had invasive breast cancer metastatic to at least one lymph node," the lawsuit reveals, and "was informed that her cancer had spread during 2014 (when she was uninsured)."

The actress, who is best known for her roles on the hit '90s TV show Beverly Hills, 90210 and later, Charmed, "was also informed that, had she been insured and able to visit her doctor, the cancer could potentially have been stopped, thus obviating the need for future treatment (including mastectomy and chemotherapy) that [Doherty] will likely have to suffer through now."

According to the suit, Doherty has been unable to work since the diagnosis and has incurred "significant" medical expenses.

"Her finances were not handled by someone she trusted handle them," says one Hollywood insider. "This was someone she trusted."

A representative for Tanner Mainstain issued this response to PEOPLE: "Tanner Mainstain is saddened to learn that Ms. Doherty is suffering from cancer and wishes her a full recovery. However, the claim that Tanner Mainstain caused her to be uninsured, prevented her from seeking medical care, or somehow contributed to her cancer is patently false. Tanner Mainstain will aggressively defend all of Ms. Doherty's claims in court."